1 // SPDX-License-Identifier: GPL-2.0 2 #include "arm64-frame-pointer-unwind-support.h" 3 #include "callchain.h" 4 #include "event.h" 5 #include "unwind.h" 6 #include <string.h> 7 8 #define perf_event_arm_regs perf_event_arm64_regs 9 #include "../../arch/arm64/include/uapi/asm/perf_regs.h" 10 #undef perf_event_arm_regs 11 12 struct entries { 13 u64 stack[2]; 14 size_t length; 15 }; 16 17 #define SMPL_REG_MASK(b) (1ULL << (b)) 18 19 static bool get_leaf_frame_caller_enabled(struct perf_sample *sample) 20 { 21 struct regs_dump *regs; 22 23 if (callchain_param.record_mode != CALLCHAIN_FP) 24 return false; 25 26 regs = perf_sample__user_regs(sample); 27 return regs->regs && regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_LR); 28 } 29 30 static int add_entry(struct unwind_entry *entry, void *arg) 31 { 32 struct entries *entries = arg; 33 34 entries->stack[entries->length++] = entry->ip; 35 return 0; 36 } 37 38 u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx) 39 { 40 int ret; 41 struct entries entries = {}; 42 struct regs_dump old_regs, *regs; 43 44 if (!get_leaf_frame_caller_enabled(sample)) 45 return 0; 46 47 /* 48 * If PC and SP are not recorded, get the value of PC from the stack 49 * and set its mask. SP is not used when doing the unwinding but it 50 * still needs to be set to prevent failures. 51 */ 52 regs = perf_sample__user_regs(sample); 53 memcpy(&old_regs, regs, sizeof(*regs)); 54 if (!(regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) { 55 regs->cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC); 56 regs->cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1]; 57 } 58 59 if (!(regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) { 60 regs->cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP); 61 regs->cache_regs[PERF_REG_ARM64_SP] = 0; 62 } 63 64 ret = unwind__get_entries(add_entry, &entries, thread, sample, 2, true); 65 memcpy(regs, &old_regs, sizeof(*regs)); 66 67 if (ret || entries.length != 2) 68 return ret; 69 70 return callchain_param.order == ORDER_CALLER ? entries.stack[0] : entries.stack[1]; 71 } 72